So I'm trying to join the top and bottom straight lines with a spiral. The problem is that the the current spiral is off centre, how do I get the centre of the spiral in line with the two vertical lines?

That's what I'm able to get to but that's not what I'm looking for. If you notice the helix is not in the centre of the two vertical lines. It is off to one side. I'm looking for it to be in the centre while still connecting to the top and bottom vertical lines.

Hi Gunter,
In the first video, I used the rotate by axis command to rotate "around your lines", and the created arc to get a center point for aligning the helix's center vertically with the lines. (Rotating the helix and leaving the lines stationary)

Here's another way where I use the edit frames rotation abilities and just rotate the entire geometry set so the lines are at the "12 o'clock" position (Aligned).... I also use "BoundingBoxCenter" instead of drawing the 3 pt. arc to get the center of the helix.

Thanks ever so much for taking the time to make and explain the video.

Unfortunately, from what I can tell the centre of the spiral is still to one side of the two vertical lines. In other words the centre of the spiral is not inline with the two lines. I'm looking for it to be in the centre while still connecting to them.